scholarly journals When Dinosaurs Walked Through Diamonds: Constraining the Age of Early Cretaceous Footprints in Volcanic Crater Sediments

2021 ◽  
Vol 6 (Spring 2021) ◽  
Author(s):  
Yasmin Jackson
Keyword(s):  
Lake Sediments ◽  
Early Cretaceous ◽  
Volcanic Rocks ◽  
Detrital Zircons ◽  
Sub Saharan Africa ◽  
Minimum Age ◽  
Sub Saharan ◽  
Age Range ◽  
Cretaceous Period ◽  
Uranium Lead Dating

The volcanic rocks of the Catoca Diamond Mine, northeastern Angola, were formed in an eruption ~118 million years ago. Above these rocks, researchers discovered Early Cretaceous mammalian, crocodilian, and sauropod dinosaur footprints in crater lake sediments. These footprints are among the relatively few vertebrate fossils from the Cretaceous Period (145-66 million years ago) found in Sub-Saharan Africa. The ~118 million-year-old age, which is the maximum age of the footprints, is provided by the uranium and lead isotope ratios in the zircon crystals from these volcanic rocks. The presence of dinosaur footprints limits the minimum age to 66 million years ago. Detrital zircons from the sediments were collected for uranium-lead dating because these lake sediments may contain not only the ~118 million-year-old zircons but also zircons from younger eruptions, which could more precisely constrain the maximum age of these sediments. Forty zircons have been analyzed from this sediment sample, yielding an age range of 2.9 billion years ago to 150 million years ago. None of these zircons was ~118 million years old. Work is currently underway to find more zircons and to determine why no ~118 million-year-old zircons have been found in the lake bed sample.

Coeval sedimentation, magmatism, and fold-thrust belt development in the Trans-Hudson Orogen: geochronological evidence from the Wekusko Lake area, Manitoba, Canada

1999 ◽  
Vol 36 (2) ◽  
pp. 293-312 ◽  
Author(s):  
Kevin M Ansdell ◽  
Karen A Connors ◽  
Richard A Stern ◽  
Stephen B Lucas
Keyword(s):  
Regional Metamorphism ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Detrital Zircons ◽  
Lake Area ◽  
Thrust Belt ◽  
Fold And Thrust Belt ◽  
Minimum Age ◽  
Flin Flon ◽  
Felsic Volcanic

Lithological and structural mapping in the east Wekusko Lake area of the Flin Flon Belt, Trans-Hudson Orogen, suggested an intimate relationship between magmatism, fluvial sedimentation, and initiation of fold and thrust belt deformation. Conventional U-Pb geochronology of volcanic rocks in fault-bounded assemblages provides a minimum age of 1876 ± 2 Ma for McCafferty Liftover back-arc basalts, and ages of between 1833 and 1836 Ma for the Herb Lake volcanic rocks. A rhyolite which unconformably overlies Western Missi Group fluvial sedimentary rocks has complex zircon systematics. This rock may be as old as about 1856 Ma or as young as 1830 Ma. The sedimentary rocks overlying this rhyolite are locally intercalated with 1834 Ma felsic volcanic rocks, and yield sensitive high resolution ion microprobe (SHRIMP) U-Pb and Pb-evaporation detrital zircon ages ranging from 1834 to 2004 Ma. The Eastern Missi Group is cut by an 1826 ± 4 Ma felsic dyke, and contains 1832-1911 Ma detrital zircons. The dominant source for detritus in the Missi Group was the Flin Flon accretionary collage and associated successor arc rocks. The fluvial sedimentary rocks and the Herb Lake volcanic rocks were essentially coeval, and were then incorporated into a southwest-directed fold and thrust belt which was initiated at about 1840 Ma and active until at least peak regional metamorphism.

Age and source of detrital zircons from the Missi Formation: a Proterozoic molasse deposit, Trans-Hudson Orogen, Canada

1992 ◽  
Vol 29 (12) ◽  
pp. 2583-2594 ◽  
Author(s):  
Kevin M. Ansdell ◽  
T. Kurtis Kyser ◽  
Mel R. Stauffer ◽  
Garth Edwards
Keyword(s):  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Detrital Zircons ◽  
Early Proterozoic ◽  
Minimum Age ◽  
Granitoid Rocks ◽  
Evaporation Technique ◽  
Single Zircon ◽  
Flin Flon ◽  
Felsic Volcanic

The Missi Formation in the Flin Flon Basin forms part of a discontinuous series of molasse-type sediments found throughout the Early Proterozoic Trans-Hudson Orogen in northern Saskatchewan and Manitoba. The Flin Flon Basin contains a sequence of proximal-fan to braided-stream fluvial conglomerates and sandstones, which unconformably overlie subaerially weathered Amisk Group volcanic rocks. Stratigraphic way-up indicators have been preserved, even though these rocks have undergone greenschist-facies metamorphism and polyphase deformation. The sedimentary rocks are crosscut by intrusive rocks, which provide a minimum age of sedimentation of 1840 ± 7 Ma.Detrital zircons from each of the six stratigraphic subdivisions of the Flin Flon Basin were analyzed using the single-zircon Pb-evaporation technique. Euhedral to slightly rounded zircons dominate each sample, and these zircons give ages of between about 1854 and 1950 Ma. The Missi sediments were thus deposited between 1840 and 1854 Ma. Possible sources for the detrital zircons are Amisk Group felsic volcanic rocks and post-Amisk granitoid rocks and orthogneisses in adjacent domains within the Trans-Hudson Orogen. However, the immature character of the sedimentary rocks, the composition of clasts, the euhedral character of many of the zircons, and the range in ages suggest that most were likely derived from Amisk Group and granitoid rocks in the western Flin Flon Domain. Rounded zircons are uncommon but provide evidence for the reworking of older Proterozoic sedimentary rocks, or a distant Archean or Early Proterozoic granitoid terrane.

scholarly journals Hysterosalpingographic patterns and relevance in the management of infertility in a Nigerian tertiary health Institution

2016 ◽  
Vol 7 (5) ◽  
pp. 70-74 ◽  
Author(s):  
D U Eduwem ◽  
A O Akintomide ◽  
D E Bassey ◽  
M I Ekott
Keyword(s):  
Imaging Modality ◽  
Demographic Data ◽  
Uterine Fibroids ◽  
Sub Saharan Africa ◽  
Medical Sciences ◽  
Non Invasive ◽  
Sub Saharan ◽  
Diagnostic Modalities ◽  
The University ◽  
Age Range

Background: Infertility is a major clinico-social problem not only in Nigeria; but the whole of the sub-saharan Africa and other parts of the world. In Nigeria it accounts for over 50% of attendance in Gynaecological clinics. Hysterosalpingography (HSG) is still a very valuable imaging modality in the work-up of women with infertility; especially in some communities in Nigeria where modern non-invasive diagnostic modalities are not readily available in most of the health institutions.Aims and Objectives: The study aims at evaluating the HSG findings among women with infertility to further highlight the relevance of this imaging modality in the management of infertility.Materials and Methods: A retrospective review of 205 consecutive Hysterosalpingograms from the University of Calabar Teaching Hospital between October 2013 and September 2015 was done. The Radiological findings and demographic data of the patients were documented and analyzed.Results: Pathologies were reported on 176 (85.8%) Hysterosalpingograms while 29 (14.14%) were normal. The age range of the patients was between 21 and 55 years and the commonest age group was 31 – 35 years. The commonest pathological findings were in the uterus; namely uterine fibroids, 86 (41.95%), uterine synaechiae, 19 (9.26%), Asherman syndrome and congenital abnormalities, 5 each (2.43%). The next commonest pathologies were those associated with tubal occlusionsConclusion: Hysterosalpingography still plays a major investigative role in the evaluation and management of women with infertility. The commonest abnormalities seen in this study were in the uterus.Asian Journal of Medical Sciences Vol.7(5) 2016 70-74

scholarly journals Cultural Adaptations of the Standard EMDR Protocol in Five African Countries

2021 ◽  
Vol 15 (1) ◽  
pp. 29-43
Author(s):  
Femke Bannink Mbazzi ◽  
Anne Dewailly ◽  
Kalkidan Admasu ◽  
Yvonne Duagani ◽  
Kizito Wamala ◽  
...  
Keyword(s):  
Health Workers ◽  
Group Discussion ◽  
Sub Saharan Africa ◽  
Mental Health Workers ◽  
Standard Protocol ◽  
African Countries ◽  
Cultural Adaptations ◽  
Study Results ◽  
Sub Saharan ◽  
Age Range

Since 2007, mental health workers in sub-Saharan Africa have been trained in eye movement desensitization and reprocessing (EMDR) therapy. This qualitative study used an Afrocentric design with thematic analysis to investigate adaptations to the EMDR standard protocol that make it culturally relevant for African clients. Participants were 25 EMDR therapists (three male, age range 32–60 years, x̄ = 44) from five African countries, who practiced EMDR for 1–11 years (x̄ = 7). All answered a survey questionnaire, eight participated in a focus group discussion, and two provided a supervision notes analysis. Participants found EMDR a useful and beneficial therapy and preferred it over other therapies because of its nonnarrative nature and quick results. We identified four areas in which African therapists consistently made adaptations to the standard protocol: wording of the protocol text, cultural expression of thoughts and emotions, stimulation choice, and simplification of quantitative scales. Based on the study results, we make numerous recommendations for cultural adaptions to the EMDR protocol. These include language changes to take into account the clients' “we oriented” communication; cultural interpretations of positive and negative thoughts and events; adding cultural activities such as dance, music, and religious practices as resourcing exercises; using hand gestures or the pictorial faces scale instead of ordinal scales; and using tapping for bilateral stimulation instead of eye movements, which were sometimes seen as “witchcraft.” The relevance of the findings for EMDR practice and training are discussed. We recommend that African researchers further study the acceptability, use, and effectiveness of EMDR in their countries.

Facial human bites. Vision on STMMs in Africa

2020 ◽  
Vol 74 (2) ◽  
pp. 1-5
Author(s):  
Pedro Clarós ◽  
Natalia Końska ◽  
Andrés Clarós
Keyword(s):  
Sub Saharan Africa ◽  
Medical Documentation ◽  
Appearance Management ◽  
Human Bites ◽  
African Populations ◽  
The Face ◽  
History Of ◽  
Free Grafts ◽  
Sub Saharan ◽  
Age Range

ABSTRACT Objectives: Human bites of the face are a frequent and serious health issue as they often compromise patients function and aesthetics as well as lead to further complications. The aim of the study is to review human bites of the face referred to our team during 112 short-term medical missions (STMMs) in Sub-Saharan Africa over the past 20 years and to discuss the epidemiology, appearance, management and outcome, including the most common complications. Methods: A retrospective medical documentation review was carried out examining all human bites of the face operated by our team during 112 STMMs from 2000 to 2019 in different countries of Sub-Saharan Africa. Results: Out of about 5500 patients medical charts 51 patients were selected due to history of human bite. Patients’ age range was 15-65 years, female to male ratio was 1, 55:1, the most often involved parts were: lips, ear and nose. Various surgical procedures were carried out including local flaps and free grafts. Infection and graft necrosis were the most common reported complication (n=4, 9,3 %). Conclusion: Human bites injuries are a serious health problem in some African populations because of their frequency and possible severity. The treatment is particularly challenging due to their potential to cause local infections, the risk they pose for transmission of systemic diseases as well as their demanding surgical management.

Radiocarbon Dates for Sub-Saharan Africa—IV

1966 ◽  
Vol 7 (3) ◽  
pp. 495-506 ◽  
Author(s):  
Brian M. Fagan
Keyword(s):  
West Africa ◽  
Fifteenth Century ◽  
Iron Age ◽  
Food Production ◽  
Sub Saharan Africa ◽  
Radiocarbon Dates ◽  
First Millennium ◽  
Sub Saharan ◽  
Age Range ◽  
First Time

The fourth radiocarbon list contains many new and important dates. Only isolated readings are still available from West Africa, but some later Iron Age sites have recently been dated. The first samples for the Kenya Highlands date food production in that region to the first millennium b.c., while important dates from Uganda confirm the traditional datings of Bigo and Bweyerore. Samples from Kilwa on the Tanzanian coast are somewhat at variance with other dating evidence.Dates for the Angola Iron Age range between a.d. 760 and the fifteenth century, while the Leopard's Kopje industry of Rhodesia has been dated for the first time.The list is completed with many isolated dates from all parts of the subcontinent.

scholarly journals Immunohistochemical characterization of KS cases seen in Nnewi Anambra state using HHV-8 LNA1 and HIV-1P24 antibodies

2021 ◽  
Vol 11 (3) ◽  
pp. 120-126
Author(s):  
Felix Emeka Menkiti ◽  
Cornelius Ozobia Ukah ◽  
Ifeoma Oluchukwu Menkiti ◽  
Ifeoma Florence Ezejiofor ◽  
Kayode A Adelusola
Keyword(s):  
Kaposi Sarcoma ◽  
Sub Saharan Africa ◽  
Human Herpes Virus 8 ◽  
Anambra State ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Health Significance ◽  
Sub Saharan ◽  
Age Range ◽  
Hiv Aids

Introduction: Kaposi sarcoma (KS) is of public health significance in sub-Saharan Africa, including Nigeria, especially in the era of HIV/AIDS. Several works have been done on the prevalence and patterns of KS both in Nigeria and other parts of Africa, with a reported significant prevalence. We employed immunohistochemistry to characterise the morphologic KS cases seen in Nnewi. Materials and Methods: The Formalin Fixed, Paraffin Embedded (FFPE) tissue blocks of all haematoxylin and eosin (H&E) diagnosed cases of KS seen in the archives of histopathology facilities in Nnewi, Anambra State over 15 year period were retrieved. Fresh sections were made from the tissue blocks of the 82 cases that met the inclusion criteria for the study, and were subjected to immunohistochemistry using HHV-8 LNA1 (Human Herpes Virus-8 Latent nuclear antigen1) and HIV-1p24 antibodies and reviewed. Results: A total of 82 KS cases were studied, 69 of which were confirmed KS cases on immunohistochemistry. KS accounted for 1.20% and 14.47% of solid malignancies and sarcomas respectively. Nearly 80% of these were HIV/AIDS-associated, 59.3% of which occurred in females. KS occurred more in the third decade with an age range of 7-74years. Conclusion: KS is quite common in our environment and is largely HIV/AIDS associated. Reducing the burden of HIV/AIDS will invariably reduce KS burden.

Chapter 3 Pre-Late Cretaceous basement terranes of the Gondwana active margin of New Caledonia

2020 ◽  
Vol 51 (1) ◽  
pp. 27-52 ◽  
Author(s):  
P. Maurizot ◽  
D. Cluzel ◽  
S. Meffre ◽  
H. J. Campbell ◽  
J. Collot ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Deep Sea ◽  
New Caledonia ◽  
Regional Scale ◽  
Volcanic Rocks ◽  
Detrital Zircons ◽  
Active Margin ◽  
Marginal Basin ◽  
Fine Grain

AbstractThe basement under the Late Cretaceous unconformity in New Caledonia consists of three amalgamated terranes. They are all oceanic, arc-related and developed offshore from the eastern Gondwana active margin during periods of marginal basin development. Téremba Terrane is composed of deep sea Permian to Mesozoic arc-derived volcanic rocks and greywackes. The Koh–Central Terrane includes at its base an ophiolite with island arc tholeiites and boninites (Koh Ophiolite) of Late Carboniferous to Early Permian age overlain by a thick sequence of greywacke (Central Range Volcaniclastic Rocks) of Permian to Late Jurassic age. The Téremba Terrane and the Koh–Central Terrane may be part of the same forearc basin, with the rocks from the Koh–Central Terrane deposited in a deeper environment. The Boghen Terrane is a metamorphic complex composed of schists, broken formations and mafic–ultramafic mélange, derived from mixed terrigenous and volcanic sources. The overall fine grain size and laminar bedding suggest deep sea and more distal deposition than the other terranes. The maximum depositional ages from detrital zircons suggest deposition during the Early Jurassic to Early Cretaceous. The terrane is interpreted as a metamorphosed subduction complex that includes blueschist and greenschist facies metamorphic rocks exhumed through the Koh–Central Terrane. At a regional scale, the nature of these three pre-Late Cretaceous terranes confirms the existing palaeogeographical reconstructions, which locate New Caledonia outboard the ocean–continent subduction that surrounded Gondwana during the Paleozoic and Early Mesozoic. A detailed analysis of these terranes and their relationship with East Australian terranes of the same age shows that a marginal basin system probably existed between mainland Gondwana and proto-New Caledonia and closed before the Late Cretaceous. A tentative detailed reconstruction of this margin during the Carboniferous–Early Cretaceous period is proposed.

scholarly journals High-Yield HIV Testing, Facilitated Linkage to Care, and Prevention for Female Youth in Kenya (GIRLS Study): Implementation Science Protocol for a Priority Population (Preprint)

2017 ◽  
Author(s):  
Irene Inwani ◽  
Nok Chhun ◽  
Kawango Agot ◽  
Charles M Cleland ◽  
Jasmine Buttolph ◽  
...  
Keyword(s):  
High Risk ◽  
Hiv Prevention ◽  
Hiv Testing ◽  
Implementation Science ◽  
Text Message ◽  
Linkage To Care ◽  
Sub Saharan Africa ◽  
Sub Saharan ◽  
Age Range ◽  
Hiv Negative

BACKGROUND Sub-Saharan Africa is the region with the highest HIV burden. Adolescent girls and young women (AGYW) in the age range of 15 to 24 years are twice as likely as their male peers to be infected, making females in sub-Saharan Africa the most at-risk group for HIV infection. It is therefore critical to prioritize access to HIV testing, prevention, and treatment for this vulnerable population. OBJECTIVE Using an implementation science framework, the purpose of this research protocol was to describe the approaches we propose to optimize engagement of AGYW in both the HIV prevention and care continuum and to determine the recruitment and testing strategies that identify the highest proportion of previously undiagnosed HIV infections. METHODS We will compare two seek recruitment strategies, three test strategies, and pilot adaptive linkage to care interventions (sequential multiple assignment randomized trial [SMART] design) among AGYW in the age range of 15 to 24 years in Homa Bay County, western Kenya. AGYW will be recruited in the home or community-based setting and offered three testing options: oral fluid HIV self-testing, staff-aided rapid HIV testing, or referral to a health care facility for standard HIV testing services. Newly diagnosed AGYW with HIV will be enrolled in the SMART trial pilot to determine the most effective way to support initial linkage to care after a positive diagnosis. They will be randomized to standard referral (counseling and a referral note) or standard referral plus SMS text message (short message service, SMS); those not linked to care within 2 weeks will be rerandomized to receive an additional SMS text message or a one-time financial incentive (approximately US $4). We will also evaluate a primary prevention messaging intervention to support identified high-risk HIV-negative AGYW to reduce their HIV risk and adhere to HIV retesting recommendations. We will also conduct analyses to determine the incremental cost-effectiveness of the seek, testing and linkage interventions. RESULTS We expect to enroll 1200 participants overall, with a random selection of 100 high-risk HIV-negative AGYW for the SMS prevention intervention (HIV-negative cohort) and approximately 108 AGYW who are living with HIV for the SMART design pilot of adaptive linkage to care interventions (HIV-positive cohort). We anticipate that the linkage to care interventions will be feasible and acceptable to implement. Lastly, the use of SMS text messages to engage participants will provide pilot data to the Kenyan government currently exploring a national platform to track and support linkage, adherence to treatment, retention, and prevention interventions for improved outcomes. CONCLUSIONS Lessons learned will inform best approaches to identify new HIV diagnoses to increase AGYW’s uptake of HIV prevention, testing, and linkage to care services in a high HIV-burden African setting. CLINICALTRIAL ClinicalTrials.gov NCT02735642; https://clinicaltrials.gov/ct2/show/NCT02735642 (Archived by WebCite at http://www.webcitation.org/6vgLLHLC9)

RTS,S/AS01, a vaccine targeting pre-erythrocytic stages of Plasmodium falciparum

2017 ◽  
Vol 1 (6) ◽  
pp. 533-537
Author(s):  
Lorenz von Seidlein ◽  
Borimas Hanboonkunupakarn ◽  
Podjanee Jittmala ◽  
Sasithon Pukrittayakamee
Keyword(s):  
Protective Efficacy ◽  
Age Groups ◽  
Sub Saharan Africa ◽  
Phase Iii ◽  
European Medicines Agency ◽  
Older Children ◽  
Pivotal Phase ◽  
Malaria Epidemiology ◽  
Maximum Benefit ◽  
Sub Saharan

RTS,S/AS01 is the most advanced vaccine to prevent malaria. It is safe and moderately effective. A large pivotal phase III trial in over 15 000 young children in sub-Saharan Africa completed in 2014 showed that the vaccine could protect around one-third of children (aged 5–17 months) and one-fourth of infants (aged 6–12 weeks) from uncomplicated falciparum malaria. The European Medicines Agency approved licensing and programmatic roll-out of the RTSS vaccine in malaria endemic countries in sub-Saharan Africa. WHO is planning further studies in a large Malaria Vaccine Implementation Programme, in more than 400 000 young African children. With the changing malaria epidemiology in Africa resulting in older children at risk, alternative modes of employment are under evaluation, for example the use of RTS,S/AS01 in older children as part of seasonal malaria prophylaxis. Another strategy is combining mass drug administrations with mass vaccine campaigns for all age groups in regional malaria elimination campaigns. A phase II trial is ongoing to evaluate the safety and immunogenicity of the RTSS in combination with antimalarial drugs in Thailand. Such novel approaches aim to extract the maximum benefit from the well-documented, short-lasting protective efficacy of RTS,S/AS01.

Sign in / Sign up

Export Citation Format

Share Document